Method and apparatus for coldrolling strip continuously



A. TEPLITZ Nov. 1, 1966 METHOD AND APPARATUS FOR COLDROLLING STRIP CONTINUOUSLY Filed Jan. 8, 1964 4 Sheets-Sheet l IIVVE/VTOR ALFRED TEFL/7'2 Al/arney QN mm: wm km mm mm mmm mmm wkm mmm wmw w:

Nov. '1, 1966 A. TEPLITZ 3,281,917

METHOD AND APPARATUS FOR COLDROLLING STRIP CONTINUOUSLY Filed Jan. 8, 1964 4 Sheets-Sheet 2 Tia-=5 //VVE/VTOR ALFRED TEFL/7'2 A ffa m ey NOV. 1, 1966 TEPLITZ 3,281,917

METHOD AND APPARATUS FOR COLD-ROLLING STRIP CONTINUOUSLY Filed Jan. 8, 1964 4 Sheets-Sheet 5 A f/am er Nov. 1, 1966 A. TEPLITZ 3,231,917

METHOD AND APPARATUS FOR COLD-ROLLING STRIP CONTINUOUSLY Filed Jan. 8. 1964 4 Sheets-Sheet 4 United States Patent ()fiFice 3,281,917 Patented Nov. 1, 1966 3,281,917 METHOD AND APPARATUS FOR COLD- ROLLING STRIP CONTINUOUSLY Alfred Teplitz, Pittsburgh, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed Jan. 8, 1964, Ser. No. 336,551 10 Claims. (Cl. 29-33) This invention relates to a cold reduction mill and, more particularly, to a rolling mill for continuously cold reducing successive coils of steel strip. The operation of cold reduction mills in present use is essentially a batch process since each coil must be individually threaded through the mill. This has several disadvantages, one of which is that considerable time is required to thread the strip through the mill so that the output of the mill is relatively low. Also, during the threading operation and the periods of acceleration and deceleration, normal strip tension between the various stands cannot be maintained. Consequently, a portion of the strip at the head and tail ends of each coil is off-gauge. Also, because of the difliculty in maintaining normal tension during threading, numerous strip breaks occur. This results in loss of material and also frequently results in marking of the mill rolls. Thus, the rolls must be changed and re-machined more often than would be required otherwise.

It is, therefore, an object of my invention to provide apparatus for continuously cold rolling a plurality of individual coils of strip.

Another object is to provide such apparatus which includes means for rapidly joining coils of strip end to end to form a continuous strip.

These and other objects will be more apparent after referring to the following description and attached drawings in which:

FIGURE 1 is a schematic top plan view of the continuous cold reduction mill of my invention with controls being indicated thereon;

FIGURE 2 is a view taken substantially along line II-II of FIGURE 1;

FIGURE 3 is a view taken substantially along line III-III of FIGURE 1;

FIGURE 4 is a front elevational view of the coil centering device of the mill on an enlarged scale;

FIGURE 5 is a view taken on the line V-V of FIG- URE 4;

FIGURE 6 is a side elevational view, partly in section, of the coil delivery cradle of the mill;

FIGURE 7 is a top plan view of the coil cradle of FIGURE 6;

FIGURE 8 is a plan view of the roller leveler of the mill, partly in section, with parts broken away for clarity;

FIGURE 9 is a view taken substantially along line IX--IX of FIGURE 8;

FIGURE 10 is a top plan view of the squaring guides of the mill;

FIGURE 11 is a view taken substantially along line XI-XI of FIGURE 10;

FIGURE 12 is a top plan view of a portion of the mill showing the jib crane in detail;

FIGURE 13 is an elevational view of a portion of the mill showing the uncoiler and jib crane in detail; and

FIGURE 14 is a detail view of a portion of the jib crane.

Referring more particularly to FIGURES 1 to 3 of the drawings, reference numeral 2 indicates a conventional motor driven conveyor for receiving coils of strip C which are to be cold rolled. The coils are arranged with their eyes horizontal and a coil centering device 4 is provided at the discharge end of the conveyor 2. As best shown in FIGURES 4 and 5 the coil centering device 4 includes a pair of side plates 6, which are arranged to move toward and away from each other. Each side plate 6 is carried by a rectangular member 8 mounted on a vertical side post 10 by means of a bearing 12. The tops of side posts 10 are connected by means of a horizontal beam 14, the beam and posts constituting a support frame for the side plates 6. An air cylinder 16 is connected to each of the members 8. A rack 18 is carried by each member 8. Each rack 18 is in mesh with a pinion 20 mounted on a vertical shaft 22. A sprocket 24 is mounted on the top of each shaft 22 and these are connected by means of a roller chain 26. The racks 18, pinions 20, sprockets 24- and chain 26 provide an equalizing device so that each of the side plates 6 will move the same distance when the air cylinders 16 are actuated. Hence, the plates 6 will always be an equal distance from the center line of the conveyor 2. When a coil C is moved to the discharge end of the conveyor 2 the cylinders 16 are actuated to move the side plates 6 inwardly, thus centering the coil. The cylinders 16 are then actuated to retract the side plates 6.

A ramp 28 is arranged at the exit end of conveyor 2 and leads to a coil cradle 30. As best shown in FIGURES 6 and 7 the coil cradle 30 includes a base plate 32 mounted for movement with a rotatable shaft 33. Gearing 34 is provided for rotating shaft 33 from a motor, not shown. A coil supporting plate 36 is pivotally mounted at one end to a bracket 38 mounted on the base plate 32. The other end of the plate 36 is connected to the piston rod 39 of an air cylinder 40 which is positioned to move the plate 36 vertically about its pivot mounting. A pair of rotatable rollers 42 are positioned in openings 44 of the plate 36 for supporting a coil to be unwound when the supporting plate 36 is in its lower position as shown in full lines in FIGURE 6. The rollers 42 are driven by a reversible motor 45, through chains 46.

A coil preparation section 48 is arranged in alignment with the conveyor 2 beyond the cradle 30. The coil preparation section 48 consists of a roller leveler 49, squaring guides 50 and a conventional guillotine up-cut crop shear 52. Crop shear 52 is set at a slight angle so that it makes its out on the bias for a purpose which will be explained later.

As best shown in FIGURES 8 and 9 the roller leveler 49 includes lower rolls 53 and upper rolls 54 which are mounted on a movable support 55 for movement toward and away from rolls 53 by means of screws 56. A pair of pinch rolls 57 and 58 are arranged on the entry side of rolls 53 and 54 The lower roll 57 is mounted with its axis in a fixed position and the upper roll 58 is mounted on a sh'dable support 59 for movement toward and away from roll 57 by means of screws 60. The supports 55 and 59 are carried by an upper frame 61 which is mounted on the piston rods 62F of four air cylinders 62 adapted to move it toward and .away from the lower rollers 53 and 57. An adjustable stop 628 is mounted on each rod 62F to limit this movement.

As shown in FIGURES 10 and 11 the squaring guide 50 includes a pair of shafts 63 having right and left hand threads 63R and 63L. The shafts 63 are rotatably mounted on a support frame 64. A pair of side guides 65 are mounted on the threads 63R and 63L and are movable toward and away from each other by rotation of shafts 63. A central strip support 66 is carried by the shafts 63 between the side guides 65. The shafts 63 are rotated by means of a motor 67 through chain 68, sprockets 69 and 70, and chain 71.

The main portion of the rolling mill is arranged at right angles to the longitudinal center line of the conveyor 2 and roller leveler 49 in line with coil cradle 30. This in cludes a standard cone type uncoiler 72 having side plates 728, a pivoted platform 72F, coil support pollers 72R, an hydraulic ram 72H for supporting the rollers 72R and an air cylinder 72C for moving the platform 72? about its pivot. Next in line is a standard coil box 73 for rotatably supporting a coil C. This is followed by a roller leveler 74 which has the same construction as roller leveler 49. A flash welder 75 having a punch 75P associated therewith is arranged on the exit side of roller leveler 74. A crop shear 76 is arranged on the exit side of welder 75 and is arranged to cut the strip on the same bias as shear 52. A squaring guide 77, preferably of the same type as squaring guide 50, follows the shear 76 and in turn is followed by a flash trimmer 78. Deflector rolls 79 and accumulator entry rolls 80 are arranged on the exit side of the flash trimmer 78 and lead to a strip accumulator 81 which is preferably of the type shown in my Patent No. 2,996,230, dated August 15, 1961. The accumulator includes arms 81A for supporting loops of strip S. Deflector rolls 82 lead from the accumulator 81 to a weld detector 83. Adjustable side guides 84, preferably of the type shown in my Patent No. 3,071,032, dated January 1, 1963, are arranged on the exit side of weld detector 83 and guides the strip to a five stand cold rolling mill 85, 86, 87, 88 and 89. Guides similar to guides 84 are preferably arranged at the entry end of each rolling mill stand, but are not shown. A thickness gauge 90 is arranged between stands 85 and 86. This gauge may be a standard X-ray thickness gauge of the type manufactured by General Electric Company. A similar thickness gauge 91 is arranged on the exit side of stand 89. A wield detector 92 is located on the exit side of thickness gauge 91. The weld detectors 83 and 92 may be conventional pin hole detectors. The weld detector 92 is followed by pinch rolls 93, flying shear 94, and recoiler 95, this preferably being as shown in my Patent No. 3,021,086, dated February 13, 1962, with the shear 94 preferably being of the type shown in my Patent No. 3,057,239, dated October 9, 1962.

A jib crane 96 is arranged between the roller levelers 49 and 74. As best shown in FlIGURES 12, 13 and 14 the jib crane 96 includes a structural frame 97 which pivotally supports one end of an -I-beam 98 by means of a vertical pivot pin 99. The axis of pivot pin 99 is aligned with the axis of shaft 33. The other end of the beam 98 is supported from a curved I-beam guide track 100' by a motor powered monorail trolley 101. A second powered monorail trolley 102 is mounted for movement on the beam 98. The trolley 102 supports a motor powered hoist 103 which in turn raises and lowers a lifting magnet 104 dependent therefrom.

Speed controls 85S, 86S, 87S, 88S and 898 are provided for controlling the speeds of stands 85, :86, 87, 88 and 89, respectively. A master control 106 is connected to the controls 85S, 865, 878, 888 and 89S. Weld detectors 83' and 92 are connected to master control 106. Screw down controls 85D, 86D, 87D, 88D and 89D are provided for the stands 85 to 89, respectively. Control 85D may be operated manually or by a gauge control 108. Screw controls 86D, 87D and 88D are operated manually while screw control 891) may be operated manually or by a tension limit control 110. The tension limit control 110 is controlled by the tension between stands 88 and 89. The gauge control 108 is adjustable for various gauges and receives signals from the weld detector 83 and thickness gauge 90. The tension limit control 110 is connected to the speed control 89S. A second gauge control 112 is connected to vary the speed of stand 89. The gauge control 112 receives signals from the gauge 91 and weld detector 92. It will be understood that the above described devices a-re conventional with the direction of the various impulses being indicated by arrows in FIGURE 1.

In operation of the mill, incoming coils of strip are placed on the conveyor 2 by a ram, truck or overhead crane. The coils are hot rolled pickled strip ranging in thickness from 0.75 to .110 in. and in width from 18 to 38 in. The average weight of a single hot rolled coil is 12,000 lbs. and the coils to be rolled may be a single hot strip coil, or two or three such coils welded together. The

conveyor 2 is operated until the first coil is discharged onto ramp 20 and comes to rest on the cradle rolls 42 of cradle 30. It will be understood that the coil C has been centered by means of the coil centering device 4 prior to being discharged onto the cradle rolls 42. The cradle rolls 42 are then rotated so as to bring the leading end of the strip into a position where it can be grasped by the magnet 104 and fed into the pinch rolls 57 and 58. The strip is passed through the leveling rolls 53 and 54 until the head end reaches the shear 52 where any damaged material is removed. The operator then raises the rolls 54 and 58 to free the strip and the squaring guides 50 are moved in against the strip to align it for a final squaring cut. The cradle rolls 42 are then rotated to withdraw the strip end from the rolls 53, 54, 57 and 58. The turn table 32 and the beam 98 are then simultaneously rotated through an angle of 90 with the magnet 104 grasping the lea-ding end of the strip. The coil is then positioned and centered in the uncoiler 72 and the coil is then ready to be fed into the mill. The gaps between the rolls of stands 85 to 89 are set up to obtain the desired strip thickness by means of screw controls 85D to 89D, respectively. The speed of the rolls is also set up by means of the masrter mill control 106, this being according to the usual practice. The guides '84 are also adjusted for the desired strip width. After the strip is fed through the mill and the mill is set up in the usual manner the rolling of prime product is commenced. The strip is fed from the uncoiler 72 at a faster rate than it is being rolled so that the accurnlulator 81 will gradually fill. While the first coil is being rolled and recoiled on coiler 95 a second coil is being prepared in the same manner as the first coil. When the first coil becomes small it is transferred from uncoiler 72 to coil box 73 by raising the cradle rolls 72R to support the coil, withdrawing the cones and side plates 72S, and then lowering the cradle rolls 72R and tipping the platform 72P so that the coil will roll by gravity into the coil box 73 where it continues to pay oil. The new coil is then transferred from cradle 30 to uncoiler 72 by tipping the platform 36 which causes the coil to roll by gravity onto the platform 72P. The cradle rolls 72R are raised to lift the new coil to the correct position for the cones to enter the eye of the coil. The cradle rolls 72R are then lowered and the new coil is in position to be threaded into the system. As the first coil approaches exhaustion the top rolls of the leveler 74 are lowered so that the final 10 to 15 ft. of the coil are flattened. Pinch rolls 80 are stopped when the tail end of the strip reaches the shear '76 and the squaring guide 77 is operated to align the strip. The end of the strip is then cropped and squared and the pinch rolls 80 are operated in reverse to bring the tail end of the strip to the welder 75. The head end of the coil on the uncoiler 72 is threaded through the leveler 74 to the welder and the flash welder operated to join the two ends. The punch 75P is operated to put a hole in the strip at the weld so it can operate the weld detectors 83 and 92 later. The pinch rolls are then operated to move the weld to 1 the flash trimmer 78 where the weld is trimmed. 1f the rolling mill has been slowed down which most often occurs it is again speeded up to normal operating speed. The pinch rolls 80 are rotated at faster than line speed until the accumulator becomes filled after which they are slowed to line speed. In the meantime another coil C is being prepared so that the above described operation can be repeated.

The strip is initially wound on the upper reel block U and then the coiler 95 is rotated to bring the upper reel block 95U to the bottom and the empty lower reel block 95L to the top. When the coil has built up to the desired length :of strip the mill is decelerated somewhat and the single cut flying shear 94 operated to sever the strip with the free end of the strip immediately entering the belt wrapper of the coiler 95 to start another coil on reel block 95L. The mill is then returned to normal operating speed and the completed coil on reel block 5U removed. The operation is then repeated.

When the weld detector 83 detects a weld in the stripit provides a signal to the master mill control 106 to slow down the line to prevent damage to the strip and/ or rolls. By welding the coils together on the bias the strip progressively passes through the rolls thus reducing its maximum impact on the rolls so that the minimum speed of operation can be greater than if the coils are welded together straight across. When the weld passes detector 92 a signail is provided to master mill control 106 to return the line to normal operating speed.

When strip of a new width is to be rolled the entry guides and hold down '84 are repositioned. If the strip is of less width the guide will be repositioned after the narrower width of strip passes the guide. If the new strip is of wider width the guide will be repositioned prior to the strip reaching the guide. This can be done automatically by providing a width gauge 120 having its output connected to a control 122 which positions side guides 84 to the desired widthv Prior to a change in strip thickness the reference points of gauge controls 108 and 112 are manually pre-set for the new thickness. The change will take place at the leadingend of a new coil and when the weld connecting this coil to the preceding coil reaches the detector 83 a signal will be provided to the gauge control 108 to automatically change it to its new pro-set value so that the screw down position of the first stand will be automatically set to the correct position. When the weld is detected by detector 92 the reference point of the gauge control 112 will be automatically changed to its new pre-set value so that the strip will leave the mill at the correct gauge.

During operation of the line the tension limit control 110 will automatically change the setting of the screws on roll stand 89 in the correct direction to restore the tension to its proper range.

It will be understood that automatic controls may be and are preferably provided so that all the operations of the line will take place automatically rather than manually as described.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A continuous cold reduction strip mill comprising means adapted to receive incoming coils of strip to be reduced, 21 first shear operatively associated with said means and adapted to crop the head end of a received coil of strip to prepare it for processing, means to support a prepared coil of strip to allow the strip to pay off therefrom, means to move a prepared coil to said last named means, a strip accumulator located on the exit side of said support means, a second shear located between said support means and said accumulator to crop the tail end of a coil being rolled, welding means adapted to weld the cropped head end of a prepared coil of strip to the tail end of the strip from a coil after it has been exhausted from the support means, a plurality of in line cold reduction stands adapted to receive strip from the accumulator and cold reduce it, means to coil the cold reduced strip, weld detector means between said accumulator and the first of said cold reduction stands, and control means adapted to reduce the rolling speed of said stands when a weld is detected by said weld detector.

2. The combination of claim 1 characterized by second weld detector means between said means to coil the strip and the last of said cold reduction stands, and second control means adapted to increase the speed of said stands when a weld is detected by said second weld detector means.

3. A continuous cold reduction strip mill comprising means adapted to receive incoming coils of strip to be reduced, a first shear operatively associated with said means and adapted to crop the head end of a received coil of strip to prepare it for processing, means to support a coil of strip to prepare it for processing, means to support a prepared coil of strip to allow the strip to pay off therefrom, means to move a prepared coil to said last named means, an accumulator for storing strip located on the exit side of said support means, a second shear located between said support means and said accumulator to crop the tail end of a coil being rolled, welding means adapted to weld the cropped head end of a prepared coil of strip to the tail end of the strip from a coil after it has been exhausted from the support means, a plurality of in line cold reduction stands adapted to receive strip from the accumulator and cold reduce it, means to coil the cold reduced strip, adjustable side guide means positioned between said accumulator and the first of said cold reduction stands, a width gauge located between said accumulator and the side guides, and control means responsive to said Width gauge adapted to adjust the side guides in accordance with the width measured.

4. A continuous cold reduction strip mill comprising means adapted to receive incoming coils of strip to be reduced, a first shear operatively associated with said means and adapted to crop the head end of a received coil of strip to prepare it for processing, means to support a prepared coil of strip to allow the strip to pay off therefrom, means to move a prepared coil to said last named means, an accumulator for storing strip located on the exit side of said support means, a second shear located between said support means and said accumulator to crop the tail end of a coil being rolled, Welding means adapted to Weld the cropped head end of a prepared coil of strip to the tail end of the strip from a coil after it has been exhausted from the support means, a plurality of in line cold reduction stands adapted to receive strip from the accumulator and cold reduce it, means to coil the cold reduced strip, selectively actuatable means to sever the cold reduced strip interposed between said coiling means and the last of said cold reduction stands, adjustable side guide means positioned between said accumulator and the first of said cold reduction stands, weld detector means between said accumulator and the first of said cold reduction stands, and control means adapted to reduce the rolling speed of said stands when a weld is detected by said weld detector.

5. A cold reduction strip mill comprising, in combination, a conveyor to receive coils of strip to be reduced, coil centering means operatively associated With said conveyor, a cradle positioned to receive coils one at a time from said conveyor, said cradle including means to pay out strip from the coil, means to rotate said cradle about a vertical axis, coil preparation means aligned with said conveyor and said cradle, said coil preparation means including first leveler rolls, a first crop shear and squaring guides between said first leveler rolls and said first crop shear, a plurality of elements lying on a line 90 from the line defined by the coil preparation means, said elements including a cone-type uncoiler adjacent said cradle, a coil box uncoiler adjacent said cone-type uncoiler on the exit side thereof, second leveler rolls adjacent said coil box, a jib crane adapted to move the head end of a coil from said coil preparation means to said second leveler rolls in timed relationship with the means to rotate said cradle, a welder adapted to weld the tail end of one coil to the head end of a second coil, said welder including means to form a weld between the coils at a bias with respect to the line of said elements, second squaring guides and a second crop shear adjacent said flash welder and adapted to prepare the tail end of a coil for welding, a flash trimmer adapted to trim the Weld flash, a strip accumulator adjacent the flash trimmer on the exit side thereof and adapted to accumulate strip from an inprocess coil, a plurality of in line cold reducing mill stands adjacent the accumulator, adjustable side guides adjacent the entry end of the first stand, a rotating drum-type shear located adjacent the last stand and selectably actuatable to shear the strip after it emerges from the last stand, and coiling means adjacent said drum-type shear on the exit side thereof, said coiling means including means to initiate the coiling of a new coil immediately after a cut by the drum-type shear.

6. The combination of claim characterized by a first weld detector located between said strip accumulator and the first of said stands, first control means adapted to reduce the rolling speed of said stands when a weld is detected by said first weld detector, at second weld detector located between said recoiler and the last of said stands, and second control means adapted to increase the rolling speed of said stands when a Weld is detected by said second weld detector.

7. A continuous cold reduction strip mill comprising means for preparing the leading ends of coils of strip for processing, a first uncoiling means for rotatably supporting a prepared coil of strip to be reduced, a second uncoiling means for rotatably supporting a prepared coil of strip to be reduced, an accumulator for storing strip located on the exit side of said first and second uncoiling means, means for selectively feeding strip from said first and second uncoiling means to said accumulator, a shear located between said accumulator and said first and second uncoiling means for cropping the tail end of a coil being rolled, welding means adapted to weld the cropped head end of a prepared coil of strip to the tail end of the strip from a coil after it has been exhausted from the uncoiling means, a plurality of in line cold reduction stands adapted to receive strip from the accumulator and cold reduce it, means to coil the cold reduced strip, adjustable side guide means positioned between said accumulator and the first of said cold reduction stands, a width gauge located between said accumulator and the side guides, and control means responsive to said width gauge adapted to adjust the side guides in accordance with the width measured.

8. A continuous cold reduction strip mill comprising means for preparing the leading ends of coils of strip for processing, a first uncoiling means for rotatably supporting a prepared coil of strip to be reduced, a second uncoiling means for rotatably supporting a prepared coil of strip to be reduced, an accumulator for storing strip located on the exit side of said first and second uncoiling means, means for selectively feeding strip from said first and second uncoiling means to said accumulator, a shear located between said accumulator and said first and second uncoiling means for cropping the tail end of a coil being rolled, welding means adapted to weld the cropped head end of a prepared coil of strip to the tail end of the strip from a coil after it has been exhausted from the uncoiling means, a plurality of in line cold reduction stands adapted to receive strip from the accumulator and cold reduce it, means to coil the cold reduced strip, weld detector means between said accumulator and the first of said cold reduction stands, and control means adapted to reduce the rolling speed of said stands when a weld is detected by said weld detector.

9. The combination of claim 8 characterized by second weld detector means between said means to coil the strip and the last of said cold reduction stands, and second control means adapted to increase the speed of said stands when a weld is detected by said second weld detector means.

10. The combination of claim 9 including adjustable side guide means positioned between said accumulator and the first of said cold reduction stands, a width gauge located between said accumulator and the side guides, and control means responsive to said width gauge adapted to adjust the side guides in accordance with the width measured.

References Cited by the Examiner UNITED STATES PATENTS 2,054,819 9/1936 Hudson 2933.21 2,214,618 9/1940 Kenyon 2933.21 2,22 1,468 11/1940 Bollinger 2933.21 2,265,052 12/1941 Anderson 2933.21

RICHARD H. EANES, JR., Primary Examiner. 

1. A CONTINUOUS COLD REDUCTION STRIP MILL COMPRISING MEANS ADAPTED TO RECEIVE INCOMING COILS OF STRIP TO BE REDUCED, A FIRST SHEAR OPERATIVELY ASSOCIATED WITH SAID MEANS AND ADAPTED TO CROP THE HEAD END OF A RECEIVED COIL OF STRIP TO PREPARE IT FOR PROCESSING, MEANS TO SUPPORT A PREPARED COIL OF STRIP TO ALLOW THE STRIP TO PAY OFF THEREFROM, MEANS TO MOVE A PREPARED COIL TO SAID LAST NAMED MEANS, A STRIP ACCUMULATOR LOCATED ON THE EXIT SIDE OF SAID SUPPORT MEANS, A SECOND SHEAR LOCATED BETWEEN SAID SUPPORT MEANS AND SAID ACCUMULATOR TO CROP THE TAIL END OF A COIL BEING ROLLED, WELDING MEANS ADAPTED TO WELD THE CROPPED HEAD END OF A PREPARED COIL OF STRIP TO THE TAIL END OF THE STRIP FROM A COIL AFTER IT HAS BEEN EXHAUSTED FROM THE SUPPORT MEANS, A PLURALITY OF IN LINE COLD REDUCTION STANDS ADAPTED TO RECEIVE STRIP FROM THE ACCUMULATOR AND COLD REDUCE IT, MEANS TO COIL THE COLD REDUCED STRIP, WELD DETECTOR MEANS BETWEEN SAID ACCUMULATOR AND THE FIRST OF SAID COLD REDUCTION STANDS, AND CONTROL MEANS ADAPTED TO REDUCE THE ROLLING SPEED OF SAID STANDS WHEN A WELD IS DETECTED BY SAID WELD DETECTOR. 